Method for separating a sliver delivered out of a sliver can at a spinning station of a spinning machine, and spinning machine

ABSTRACT

A spinning machine and method separate a sliver delivered out of a sliver can at a spinning station of the spinning machine. The sliver is delivered out of the sliver can with a supply device at the spinning station in a delivery direction to a spinning device, and is guided by a sliver guide between the sliver can and the supply device. The sliver is clamped in the supply device at the spinning station. In order to separate the sliver, the supply device is driven counter to the delivery direction, wherein the sliver is returned by the supply device and, as a result, the clamping of the sliver in the supply device is released.

FIELD OF THE INVENTION

The present invention relates to a method for separating a sliverdelivered out of a sliver can at a spinning station of a spinningmachine, wherein the spinning station includes a spinning device and asupply device, by means of which the sliver is delivered out of thesliver can at the spinning station and in which the sliver is clamped atthe spinning station. Moreover, the invention relates to a spinningmachine that includes a plurality of adjacently arranged spinningstations and sliver cans placed in at least one row underneath thespinning stations, wherein the spinning stations each include a supplydevice for delivering a sliver out of one of the sliver cans at thespinning station.

BACKGROUND

At spinning machines, it can become necessary for various reasons toseparate the sliver delivered at the spinning station. For cleaningpurposes, for example, it can become necessary to separate the sliver,clean the spinning station, and subsequently piece the sliver. It canalso become necessary within the scope of a lot change or during anexchange of the sliver can to separate the sliver if the lot change orthe exchange of the sliver can is to be carried out with a sliver canthat is not yet completely empty. It is possible, for example, to simplyallow the sliver to tear when the sliver can to be exchanged is removedfrom the spinning machine. A separation of this type takes place in acompletely undefined manner, however, and can result in yarn defects asthe remaining sliver residue is spun.

DE 25 21 851 A1 therefore describes separating the sliver in acontrolled manner with a smooth cut by means of a separating device. Forthis purpose, an appropriate separating device is to be arranged at eachspinning station. The remaining sliver residue is spun, wherein, due tothe smoothly cut sliver end, the yarn forms a thick place at the end ofthe yarn in the form of a fiber bundle.

DE 39 28 648 A1 describes a can change process in which sliver cans areexchanged by means of a can change trolley. The can change trolley isdesigned to be able to exchange sliver cans from the front row andsliver cans from the back row. The can change trolley includes aseparating device in order to achieve a defined separation of the sliverat sliver cans that are not yet completely empty. Yarn defects can arisein this case as well.

SUMMARY OF THE INVENTION

A problem addressed by the present invention is therefore that ofeliminating the disadvantages known from the prior art, in particular ofavoiding yarn defects due to the separation of the sliver. Additionalobjects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

The problems are solved using a method and a spinning machine having thefeatures described and claimed herein.

In a method for separating a sliver delivered out of a sliver can at aspinning station of a spinning machine, the spinning station includes aspinning device and a supply device, by means of which the sliver isdelivered out of the sliver can at the spinning station in a deliverydirection and in which the sliver is clamped at the spinning station. Itis provided that, in order to separate the sliver, the supply device isdriven counter to the delivery direction, wherein the sliver is returnedby means of the supply device and, as a result, the clamping in thesupply device is released.

In an appropriate spinning machine that includes a plurality ofadjacently arranged spinning stations and that includes sliver cansplaced in at least one row underneath the spinning stations, thespinning stations each include a supply device for delivering a sliverout of one of the sliver cans at the spinning station. It is providedthat the spinning station and/or the spinning machine include(s) acontrol unit for carrying out the above-described method.

In other words, in order to separate the sliver, the supply device isoperated counter to the delivery direction during production. As aresult, before the sliver enters the spinning device, the sliver isseparated from the spinning device and no sliver residue remains at thespinning station. It is therefore neither necessary to remove aremaining sliver residue from the spinning station, nor can a remainingsliver residue result in yarn defects. Since, in addition, due to thereturn, the clamping of the sliver in the supply device issimultaneously also released, the sliver, which has now been separated,can be returned in entirety to the sliver can during a sliver canchange.

For example, at a rotor spinning machine, the supply device is a feederthat is briefly operated counter to its regular direction of rotationduring production in order to carry out a return. As a result, thesliver that is clamped during operation between a feed roller of thefeeder and a feed trough assigned to the feed roller is separated fromthe spinning device immediately before the sliver enters the spinningdevice and is simultaneously conveyed out of the clamping point. Theclamping of the sliver in the supply device is therefore simultaneouslyreleased, and so the end of the separated sliver is free.

The method can also be used on an air-jet spinning machine. The supplydevice is a drafting system in this case, which is briefly drivenbackward in order to separate the sliver, as the result of which thesliver entering the spinning device is returned. The sliver is clampedin the roller pairs of the drafting system in this case. Due to thereturn of the sliver and driving the drafting system in the directioncounter to the regular delivery direction, the sliver is separatedimmediately before the sliver enters the spinning device in this case aswell and is conveyed out of the drafting system by means of the rollerpairs of the drafting system. As a result, the clamping of the sliver inthe supply device is simultaneously released, and so the end of theseparated sliver is free.

Advantageously, in this case, a draft between the various roller pairsof the drafting system is established in reverse order in comparison tothe draft during regular production. As a result, it can be ensured thatthe sliver does not become jammed during the return, which can occur,for example, at a condenser assigned to the drafting system.

Preferably, the spinning device is initially stopped before the supplydevice is driven counter to the delivery direction. The units of thespinning station can be shut down in a controlled manner and incoordination with one another. Yarn defects, which could otherwise ariseduring the delivery of the sliver, can be avoided as a result. This isnot necessary, however. A thread break can also be generated due to thedriving counter to the delivery direction.

It is also advantageous when the sliver, after having been separated, isunthreaded from a sliver guide of the spinning station. As a result, thesliver is no longer connected to the spinning machine at any point and,as a result, can be easily removed from the spinning machine togetherwith the sliver can to be exchanged during a can change.

It is advantageous when the separation of the sliver is carried outwithin the scope of an automatic can change process. An at leastpartially emptied sliver can to be removed is removed from the spinningmachine and replaced by a full sliver can. By means of the method, thesliver can be separated in a reliable manner and free of residue, i.e.,without any sliver residue remaining. The sliver cans can be easilyexchanged as a result, even though the sliver cans still contain someresidual product. Due to a preventive sliver can change of this type,downtimes of the spinning devices, which can occur when the sliver cansare emptied, can be avoided. The productivity of the spinning machinecan be increased as a result.

It is also advantageous when a remaining sliver length of the sliver ispredefined and the can change process is initiated as soon as thepredefined remaining sliver length has been attained. The specificationof a defined remaining sliver length contributes to avoiding thesituation in which the sliver cans are completely emptied and toavoiding premature sliver can changes.

For this purpose, a remaining sliver length of the sliver at which anautomatic can change process is to be initiated is advantageouslypre-defined in the control unit.

It is also advantageous when the spinning station includes a measuringdevice, by means of which the remaining sliver length of the sliver isascertainable. The measuring device is in control connection with thecontrol unit, in order to initiate the automatic can change process.

According to one enhanced embodiment of the method, it is advantageouswhen the sliver is unthreaded by means of at least one handling deviceof the spinning machine. As a result, the sliver can be advantageouslyseparated from the spinning machine already before an operator or a canchanger arrives.

With respect to the spinning machine, the spinning machine and/or thespinning station advantageously include(s), for this purpose, at leastone handling device for unthreading the sliver from a sliver guide ofthe spinning station. The handling device can be arranged, for example,at the spinning machine, in particular at a single spinning station,and, as a result, can advantageously unthread the sliver directly afterthe sliver has been returned. A handling device that serves multiplespinning stations and is arranged in the area of a spinning station isalso conceivable. It is also possible, however, that the spinningmachine includes a movable service unit, at which the at least onehandling device is mounted. As a result, the handling device of themovable service unit can preferably also unthread the sliver from thesliver guide before a movable can changer arrives.

According to another enhanced embodiment of the method, it isadvantageous when the sliver is unthreaded by means of at least onehandling device of a movable can changer. A can changer, which is alsoprovided, includes, for this purpose, a handling device, for example, aclamp for the sliver, for unthreading a separated sliver from the sliverguide. As a result, the spinning machine does not require handlingdevices that are specific to a spinning station or arranged in a movableservice unit and, thus, can be designed to be simpler and morecost-effective. Only a single handling device is necessary at themovable can changer.

It is also conceivable that the at least one handling device of thespinning machine cooperates with the at least one handling device of thecan changer in order to carry out the unthreading. This is conceivablefor a handling device arranged in a movable service unit and for aspinning station-specific handling device. Two handling devices arrangedat the spinning machine could also cooperate. For example, a handlingdevice in the movable service unit could perform the unthreading processjointly with the handling device at the spinning station.

As described above, it is advantageous when the sliver is unthreadedalready before the can change process is carried out. This isadvantageous, in particular, when the unthreading is carried out bymeans of a handling device of the spinning machine, since, as a result,the actual can change process can be started immediately after the canchanger arrives and can be carried out faster.

According to another advantageous enhanced embodiment, the sliver isunthreaded during the can change process. This is advantageous, inparticular, when the unthreading is carried out by a handling device ofthe can changer, since this requires no additional time and thedowntimes of the spinning stations can be kept low. It can beadvantageous to unthread the sliver only during the can change processalso when unthreading the sliver by means of a handling device of thespinning machine. The can change process can also be carried out withoutdelay in this case.

In principle, it is also conceivable, however, to unthread the sliverfrom the sliver guide only after the actual can change has been carriedout, in particular when the handling device is arranged at the canchanger.

If the handling device is provided at the can changer, it isparticularly advantageous when the sliver is clamped by a can gripper ofthe can changer to unthread the sliver from the sliver guide. As aresult, the sliver can be advantageously unthreaded from the sliverguide by removing the sliver can from the spinning station. For thispurpose, advantageously, with respect to the can changer, a clamp isarranged at a can gripper of the can changer or the can gripper itselfforms a clamp.

It is particularly advantageous when the sliver is clamped by the cangripper at the sliver can to be removed and is pulled out of the sliverguide due to the removal of the sliver can.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention are described in the followingexemplary embodiments, wherein:

FIG. 1 shows a schematic front view of a spinning machine;

FIG. 2 shows a schematic front view of a spinning station of a spinningmachine before the separation of the sliver;

FIG. 3 shows the spinning station from FIG. 2 after the separation ofthe sliver;

FIG. 4 shows a schematic front view of a spinning station that includesa handling device for unthreading the sliver after the separation of thesliver;

FIG. 5 shows the spinning station from FIG. 4 after the unthreading ofthe sliver;

FIG. 6 shows a section of a spinning machine with a movable service unitthat includes a handling device for unthreading the sliver;

FIG. 7 shows a schematic side view of a spinning station that includes acan changer according to a first embodiment before an automatic canchange process is carried out;

FIG. 8 shows the spinning station from FIG. 7 during the automatic canchange process;

FIG. 9 shows a schematic side view of a spinning station that includes acan changer according to a second embodiment before an automatic canchange process is carried out;

FIG. 10 shows the spinning station from FIG. 9 during the automatic canchange process;

FIG. 11 shows a schematic side view of a spinning station that includesa can changer according to a third embodiment before an automatic canchange process is carried out; and

FIG. 12 shows the spinning station from FIG. 11 during the automatic canchange process.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or moreexamples of which are shown in the drawings. Each embodiment is providedby way of explanation of the invention, and not as a limitation of theinvention. For example features illustrated or described as part of oneembodiment can be combined with another embodiment to yield stillanother embodiment. It is intended that the present invention includethese and other modifications and variations to the embodimentsdescribed herein.

In the following description of the exemplary embodiments, features thatare identical or at least comparable with respect to their design and/ormode of operation are provided with identical reference characters.Moreover, these are explained in detail only at their first mention,while only the differences from the previously described exemplaryembodiments are discussed in the subsequent exemplary embodiments.Moreover, for the sake of clarity, often only one or only a few ofseveral identical components and/or features is/are labeled.

FIG. 1 shows a schematic front view of a spinning machine 1 thatincludes a plurality of adjacently arranged spinning stations 2. Thespinning stations 2 are arranged, in the usual way, between two frames11 on one or also on both longitudinal side(s) of the spinning machine1. Each of the spinning stations 2 includes, in the usual way, a supplydevice 5, by means of which a sliver 4 is delivered out of a sliver can3 to a spinning device 6. The sliver cans 3 are placed underneath thespinning stations 2 in one row or also in multiple rows. By means of thespinning device 6, a yarn 8 is spun out of the sliver 4, the yarn 8 alsobeing wound, as known, onto a bobbin 7 by means of a winding device. Thesliver 4, after exiting the sliver can 3 and before reaching the supplydevice 5, is guided through a sliver guide 9 at the spinning station 2,the sliver guide 9 being arranged underneath the supply device 5 in thepresent example. In the spinning machine 1 shown, a measuring device 17is also arranged at each spinning station 2, by means of which aremaining length of the sliver 4 still located in the particular slivercan 3 can be ascertained. This can be carried out, for example,indirectly, by measuring the running length of the sliver 4 that hasalready been processed.

In the present example, the spinning machine 1 also includes a movableservice unit 12, which can carry out maintenance operations, such as,for example, bobbin changes, cleaning processes, or, depending on thedesign of the spinning machine 1, spinning start-up processes as well.The spinning stations 2 of the spinning machine 1 can preferably also bedesigned as at least semi-autonomous spinning stations 2, however, whichcan then automatically carry out at least one spinning start-up process.The spinning stations 2 can also be designed to be fully autonomous, andso a movable service unit 12 is not absolutely necessary.

The spinning machine also includes at least one control unit 16 forcontrolling the spinning stations 2 and, possibly, the movable serviceunit 12. In the present case, a control unit 16 is apparent as a centralmachine control system of the spinning machine 1. Control units 16 canadditionally also be provided at the spinning stations 2, however, inorder to control the working elements of the spinning stations, forexample, the measuring device 17, the supply device 5, the spinningdevice 6, and others. Each spinning station 2 can include a separatecontrol unit 16 as a workstation control system or one control unit 16can be provided as a workstation control system for a group of spinningstations 2.

The spinning machine 1 can be designed as a rotor spinning machine, andso a feeder is provided as a supply device 5. The spinning machine 1could also be designed as an air-jet spinning machine, however, whereinthe supply device 5 would then be designed as a drafting system.

FIG. 2 shows a method for separating a sliver 4 delivered out of asliver can 3 at a spinning station 2, using the example of a workstation2 at a rotor spinning machine. The sliver 4 is guided through the sliverguide 9 before the sliver 4 reaches the supply device 5 and is fed bythe supply device 5 to the opening device 19. The supply device 5 isdesigned as a feeder in the present case and includes a feed roller 21and a feed trough 20, between which the sliver 4 is clamped. The feedroller 21 is driven in the regular direction of rotation of the feedroller 21 during the production operation, as the result of which thesliver 4 is fed to the opening roller 19 in the delivery direction LR.The sliver 4 is opened into individual fibers by the opening roller 19,the individual fibers then being fed to the spinning device 6.

If the sliver 4 is now to be separated at the spinning station 2, thespinning station 2 is initially stopped. This can be carried out, forexample, by stopping the feed roller 21, resulting in a thread break. Itis also possible, however, to shut down the working elements of thespinning station 2 in a controlled manner. For this purpose, the controlunit 16 of the spinning machine 1 and/or of the spinning station 2 is incontrol connection, among other things, with the spinning device 6 andwith the supply device 5, as indicated by the dashed lines. The spinningstation 2 is now stopped, but the sliver end 10 (see FIG. 3 ) of thesliver 4 is still clamped in the supply device 5, however. In order toseparate the sliver 4, the supply device 5, namely the feed roller 21 inthis case, is now briefly driven counter to the regular direction ofrotation of the supply device 5, as indicated by the arrow.

As shown in FIG. 3 , as a result, the sliver 4 is returned counter tothe delivery direction LR until the sliver end 10 has been conveyed outof the supply device 5 and the clamping in the supply device 5 has beenreleased. The sliver end 10 is now free and can be removed from thesliver guide 9, for example, within the scope of a can change process.

As already indicated in conjunction with FIG. 1 , the separation of thesliver 4 can take place due to the attainment of a remaining lengthpredefined in the control unit 16, the remaining length being detectedby a measuring device 17 (not represented here), which, for thispurpose, is also connected to the control unit 16. This can also takeplace, however, due to a signal predefined by a control unit 16, forexample, within the scope of a lot change, or can also be triggeredmanually by an operator. In any case, when the sliver 4 is separated bymeans of a return, no sliver residue is spun, and so defective places inthe yarn 8 are avoided. Thereafter, if the sliver 4 is to be unthreadedfrom the sliver guide 9, for example, within the scope of an automaticcan change process or also for cleaning purposes, multiple possibilitiesare conceivable according to the method.

According to a first variant of the method and of the correspondingspinning machine 1, which is described with reference to FIGS. 4 and 5 ,the sliver 4 is removed from the sliver guide 9 by means of a spinningstation-specific handling device 13. The handling device 13 is designedas a swivelable clamp 18 in this case. As soon as the return of thesliver 4 has ended and the sliver end 10 is free, the clamp 18 can beactuated by the control unit 16 and the sliver 4 can be clamped.Thereafter, the sliver end 10 is unthreaded from the sliver guide 9 byswiveling (see arrow in FIG. 4 ) the handling device 13.

This condition is shown in FIG. 5 . Once the sliver 4 has beencompletely separated from the spinning station 2, the clamp 18 can bereleased so that the sliver 4 automatically drops into the sliver can 3due to gravity. Alternatively, the handling device 13 can also bedesigned, however, such that the handling device 13 places the sliver 4with the sliver end 10 directly in the sliver can 3.

According to a second variant of the method and of the correspondingspinning machine 1, the handling device 13 is arranged in a movableservice unit 12. This is represented in FIG. 6 . The handling device 13is designed as a swivelable clamp 18 in the present case as well. Inorder to actuate the clamp, the handling device 13 is preferablyconnected to a control unit 16 (not shown here) of the service unit 12,which communicates with the control unit 16 of the spinning machine 1and/or with the control unit 16 of the workstation 2. Furthermore, theunthreading can take place as described with reference to FIGS. 4 and 5.

The clamp 18 described in FIGS. 4 through 6 can be designed, of course,not only to be swivelable, but rather also movable in another way, inorder to unthread the sliver 4 from the sliver guide 9. Moreover, thehandling device 13 also does not absolutely need to include a clamp 18.A finger that is swivelable, or movable in any other way, into the pathof the sliver 4 and deflects and, as a result, unthreads the sliver 4 isalso conceivable. The unthreading of the sliver 4 can be carried outbefore, during, or after an automatic can change process, provided thata can changer 14 (see FIGS. 7 through 12 ) is still positioned at thespinning station 2.

FIGS. 7 and 8 show another embodiment of the method and of a movable canchanger 14, in which the handling device 13 is arranged at the canchanger 14. The can change process can be initiated, for example, assoon as the attainment of a predefined remaining sliver length has beenregistered by the measuring device 17. The desired remaining sliverlength can be stored, for example, in the control unit 16 of thespinning machine 1 and/or of the spinning station 2. When the slivercans 3 have been placed in multiple rows, however, a preventive canchange of the sliver cans 3 of the other rows can also be carried out ifa sliver can 3 has emptied in only one of the rows at the same standingarea. A preventive can change after a certain operating time is alsopossible.

The can changer 14 is summoned for the automatic can change process, thecan changer 14 carrying a full sliver can 3 b. The can changer 14 alsoincludes a can gripper 15 to handle the sliver cans 3 and exchange thesliver can 3 a to be removed and replaced by the full sliver can 3 b. Inthe representation shown in FIG. 7 , the can changer 14 has becomepositioned in front of the relevant spinning station 2. The sliver 4 hasalready been separated at the relevant spinning station 2 due to thereturn carried out by means of the supply device 5 and is now connectedto the spinning station 2 only at the sliver guide 9. In order tounthread the sliver 4, the handling device 13 is arranged at the canchanger 14 directly at the can gripper 15 in the present case. The cangripper 15 includes a clamp 18, which clamps the sliver 4 underneath thesliver guide 9.

If, as represented in FIG. 8 , the sliver can 3 a to be removed is nowremoved by means of the can gripper 15, the sliver 4 is simultaneouslyunthreaded by means of the clamp 18 fastened at the can gripper 15 dueto the movement of the can gripper 15.

FIGS. 9 and 10 show another embodiment of the method and of a movablecan changer 14, in which the handling device 13 is arranged at the canchanger 14. A clamp 18, as a handling device 13, is arranged directly atthe can gripper 15. A situation is represented in FIG. 9 , in which thesliver 4 has already been separated due to the return carried out bymeans of the supply device 5 and the can gripper 15 of the can changer14 has just gripped the sliver can 3 a to be removed. The sliver can 3 ato be removed is now pulled out, to some extent, from its standing areaunderneath the spinning machine 1, as indicated by the arrow.

As soon as the can gripper 15, with the sliver can 3 a, is located inthe position represented in FIG. 10 , in which the sliver can 3 a is nolonger located underneath, but rather in front of the spinning machine1, the sliver 4 can be clamped by means of the clamp 18. In the presentcase, the sliver 4 is clamped directly at the front edge of the slivercan 3 a to be removed. Due to the sliver can 3 a being pulled outfarther, the sliver 4 is also simultaneously unthreaded from the sliverguide 9. The sliver 4, more precisely, the sliver end 10, then remainsoutside of the sliver can 3 a. In deviation from the embodiment shown,it is also possible, of course, to design the handling device 13 suchthat the handling device 13 places the sliver end 10 in the sliver can 3a.

FIGS. 11 and 12 show another embodiment of the method and of a movablecan changer 14, in which the handling device 13 is arranged at the canchanger 14. In this case, the handling device 13 includes a swivelablefinger, which deflects the sliver 4 and, as a result, unthreads thesliver 4 from the sliver guide 9. FIG. 11 shows a situation in which thesliver can 3 a to be removed has just been gripped by means of the cangripper 15.

FIG. 12 shows a situation, however, in which the sliver 4 has alreadybeen unthreaded from the sliver guide 9 by way of the finger of thehandling device 13 having been swiveled.

The present invention is not limited to the represented and describedexemplary embodiments. In deviation from the embodiments shown in FIGS.7 through 12 , a handling device 13 arranged at the can changer 14 couldalso include a swivelable clamp 18 similarly to FIGS. 4 through 6 .Moreover, it would be conceivable to provide the handling device 13 atthe can changer 14 separately from the can gripper 15. If the handlingdevice 13 is provided at the can changer 14, it is also advantageouswhen the unthreading of the sliver 4 is carried out before or during theautomatic can change process. It is also conceivable, however, to carryout the unthreading of the sliver 4 only after the actual can changeprocess, as soon as the sliver can 3 a has been accommodated on the canchanger 14. Further modifications within the scope of the claims arealso possible, as is any combination of the features, even if they arerepresented and described in different exemplary embodiments.

List of reference characters 1 spinning machine 2 spinning station 3spinning station 3 a sliver can to be removed 3 b full sliver can 4sliver 5 supply device 6 spinning device 7 bobbin 8 yarn 9 sliver guide10 sliver end 11 frame 12 movable service unit 13 handling device 14 canchanger 15 can gripper 16 control unit 17 measuring device 18 clamp 19opening roller 20 feed trough 21 feed roller LR delivery direction

1–16. (canceled)
 17. A method for separating a sliver delivered out of asliver can at a spinning station of a spinning machine, comprising:delivering the sliver out of the sliver can with a supply device at thespinning station in a delivery direction to a spinning device; with asliver guide, guiding the sliver between the sliver can and the supplydevice; clamping the sliver in the supply device at the spinningstation; and in order to separate the sliver, driving the supply devicecounter to the delivery direction, wherein the sliver is returned by thesupply device and, as a result, the clamping of the sliver in the supplydevice is released.
 18. The method according to claim 17, wherein, afterthe separation of the sliver, the sliver is unthreaded from the sliverguide of the spinning station.
 19. The method according to claim 17,wherein the separation of the sliver takes place during an automatic canchange process at the spinning station.
 20. The method according toclaim 17, further comprising pre-defining a remaining length of thesliver to be left in the sliver can, wherein the can change process isinitiated when the predefined remaining sliver length has been reached.21. The method according to claim 18, wherein the sliver is unthreadedby a handling device configured with the spinning machine.
 22. Themethod according to claim 18, wherein the sliver is unthreaded by ahandling device configured on a movable can changer.
 23. The methodaccording to claim 22, wherein the sliver is clamped by a can gripper ofthe can changer in order to unthread the sliver from the sliver guide.24. The method according to claim 22, wherein the sliver is unthreadedfrom the sliver guide before a can change process.
 25. The methodaccording to claim 22, wherein the sliver is unthreaded during a canchange process.
 26. The method according to claim 17, wherein the sliveris clamped by a can gripper at the sliver can and is pulled out of thesliver guide upon removal of the sliver can from the spinning station.27. A spinning machine, comprising: a plurality of adjacently arrangedspinning stations; a row of sliver cans placed i underneath the spinningstations; each of the spinning stations comprising a supply device thatdelivers a sliver out of one of the sliver cans at the spinning station,a spinning device, and a sliver guide in which the sliver is guidedbetween the sliver can and the supply device; a control unit configuredto operate the spinning machine for: delivering the sliver out of thesliver can with the supply device at the spinning station in a deliverydirection to the spinning device, wherein the sliver is guided by thesliver guide between the sliver can and the supply device; clamping thesliver in the supply device at the spinning station; and in order toseparate the sliver, driving the supply device counter to the deliverydirection, wherein the sliver is returned by the supply device and, as aresult, the clamping of the sliver in the supply device is released. 28.The spinning machine according to claim 27, wherein the control unitdefines a remaining sliver length of the sliver to remain in the slivercan at initiation of an automatic can change process.
 29. The spinningmachine according to claim 28, wherein each spinning station comprises ameasuring device that determines when the remaining sliver length isreached.
 30. The spinning machine according to claim 27, furthercomprising a handling device that unthreads the sliver from the sliverguide.
 31. A movable can changer configured to carry out an automaticcan change process at a spinning machine, comprising a handling devicethat is movable to a position to engage and unthread a separated sliverfrom a sliver guide at a spinning station of the spinning machine. 32.The movable can changer according to claim 31, wherein the handlingdevice comprises a clamp.